multiple UART with one microcontroller.

[HIREN DAVE]

Hello,

I want to connect 8 GSM modems with 1 microcontroller. but my microcontroller has only one UART. So i need multiple UART. which are the techniques? is there any direct IC available?

 

[ScOe]

Do you want to send distinct message to each modem ? If yes, then you might consider something like http://ics.nxp.com/products/bridges/i2c.spi.slave.uart.irda.gpio/ The chip is **broken link removed**

 

[embpic]

yes u can use multiple uart channel but u have create it manual that is software uart channel.but u will don't have interrupt for that like uart which is inbuild having.
which crystal u are using and which controller u are using.
on that basis u can create soft-uart.

 

[Bharathi1]

HI sir i have also planned to use single micro controller for multiple UART, i got to know from other site that i can use dual multiplexer ,but i am facing problem because now am interfacing 3 GSM modem with microcontroller using mux 4052 and 232 converter. actual the problem is i can't give +12V and -12V supply to the mux input. please tell me is there any other multiplexer which will support to connect GSM output to MUX?

 

[betwixt]

The mux should be on the microcontroller side, not the GSM side!

Another alternative to look at is the MAX3100 and its successors. They use three wire SPI interfaces and can be daisy chained or run in parallel with different select signals. They have FIFO and can share a single IRQ signal. Very easy to use!

Brian.